1. Field of the Invention
The present invention relates to a novel production method for optical waveguides and gratings and related devices. More particularly, the invention relates to a method of fabricating optical devices including waveguides and gratings using photosensitive polymeric dielectric compositions using electron beam lithography.
2. Description of the Prior Art
Optical devices employing waveguides and/or some type of wavelength selective device such as a grating are of critical importance to the fiber optic telecommunications industry. Optical telecommunications systems employing technologies such as Wavelength Division Multiplexing (WDM) use a variety of wavelength selective optical devices. Lowering the cost of telecommunications systems is a critical factor in delivering more services to customers at a lower cost-per-customer. The cost of installing, upgrading or expanding a fiber optic network system is typically dominated by 2 factors: cost of installation and cost of the fiber optic components. Lowering the cost of fiber optic components could make a significant impact on cost-per-customer of delivering additional telecommunications services.
One factor involved in the cost of manufacturing fiber optic components employing integrated optical elements is the cost of fabricating the actual chip that contains the optical waveguides, gratings, etc. Precise control over the fabrication process is needed and any process for making such devices should be able to be made in high volumes with as few steps as possible. In addition, any manufacturing platform should be versatile enough to allow for many different types of devices to be easily fabricated, enabling a variety of new devices to be developed.
In order to address this need, many processes for fabricating integrated waveguides using many materials have been explored. Silicon On Insulator (SOI) technology has been successfully used to fabricate a variety of waveguides and waveguide devices. In addition, polymer based waveguides have also been explored. One material in particular, which has been considered for use as an optical waveguide, is bisbenzocyclobutene (BCB). This material has been shown to exhibit low optical loss, excellent planarization characteristics and the ability to withstand high optical power densities.
Yet another very important aspect of many optical devices is the active tuning or changing of their optical characteristics by using some controllable optical, electrical, thermal and/or mechanical property. This is particularly critical for telecommunications applications such as dense wavelength division multiplexing (DWDM). More specifically, tunable optical filters for DWDM channel separation/multiplexing or tunable gain flattening filters for optical amplifiers are very important to emerging telecommunications systems. In addition, tunable dispersion compensation gratings are very important for long haul multi-gigabit telecommunications.
Accordingly, it is an object of the present invention to provide a new and improved method of making optical waveguides using dielectric materials.
Another object of the present invention is to provide a method of making optical devices having waveguides and gratings using dielectric materials.
A further object of this invention is to provide a method of making optical devices having waveguides and gratings where the accuracy of the physical dimensions of the gratings is between 5 nm and 50 nm.
A further object of the present invention is to provide a method of making optical devices having waveguides and gratings using dielectric materials and electron beam lithography.
A further object of this invention is to provide optical devices and methods for manufacturing those optical devices whose optical characteristics can be tuned.